ABSTRACT Despite significant progress in understanding cancer and cancer-treatment associated cognitive dysfunction (CACD), concerns have been raised about the adequacy of traditional neuropsychological tests to accurately detect cognitive changes reported by patients. Memory deficits are the most commonly reported cognitive problems among survivors; however, assessment with traditional neuropsychological measures of memory has frequently demonstrated performance in the normal range. We propose that changes in attentional processes interfere with efficient and effective encoding of information in memory. Therefore, survivors? perception of memory problems is accurate, but related to deficits in attention rather than memory. Traditional neuropsychological measures: 1) Can have low test-retest reliability over clinically relevant timeframes leading to large measurement error; 2) Focus on coarsely defined domains of cognitive function while ignoring the subcomponents of attention critical for later recall; 3) Are unable to measure pre-attentive processes like sensory gating / filtering; and 4) Do not correlate with self-report of cognitive problems. To address these limitations, we have developed a battery of well-studied and validated cognitive experimental measures, the Sensory-Attention-Executive (SAE) battery, which will allow for decomposition of sensory, attentional and executive sub-processes that underlie efficient learning and encoding of information. We will examine cognitive changes associated with adjuvant treatment for postmenopausal breast cancer patients treated with chemotherapy (CT+: N=100) and not treated with chemotherapy (CT-: N=100), who will be assessed prior to adjuvant treatment, 1 month post-chemotherapy (yoked for CT- patients) and 12 and 24 months post- enrollment with the SAE battery and traditional neuropsychological measures. Matched healthy controls (N=100) will be assessed over similar timeframes. The objective of this proposal is to evaluate the following specific aims: Aim 1: Examine alterations in subcomponents of attention and executive control using the SAE battery at pretreatment and over time in CT+ and CT- compared to matched, healthy controls; Aim 2: Examine the prevalence of impairment at pretreatment and over time utilizing the SAE battery versus traditional neuropsychological measures in CT+ and CT- compared to matched, healthy controls; Aim 3: Examine the relationship of measures of pre-attentive processing to later, performance-based measures of attention and memory from the SAE and traditional batteries; and Aim 4: Examine associations between self-report measures (Sensory Gating Inventory and FACT-Cog) and performance on the SAE battery and traditional neuropsychological measures. This research is significant because use of the SAE measures could more precisely identify subcomponents of cognitive processes associated with CACD leading to tailored treatments and is innovative because it utilizes assessments base on cognitive neuroscience allowing for assessment of subcomponent cognitive processes along the information processing chain, including pre-attentive processes.